Lock fob doobs



'UNITED STATES PATENT OFFICE.

JAS. J'. HAMILTON, OF NEWCASTLE, INDIANA.

LOCK FOR DOORS.

.Specification of Letters Patent JNO. 20,063, .dated Apr'dlzf, 21'858.V

To all whom "it may concern:

Be it known that I, J Air-ns J. HAMILTON, of Newcastle, in the county fof Henry and State of Indiana, have invented :a ,new and .useful Improvement in Locks; and I Ido i .hereby declare the following to -bera correct ldescription of the same, referencebeinghad .to `the accompanying drawings, in which- Figure l, isagperspective viewof the interior ofthe lock complete; Fig. 2 is a ver tical longitudinal fsection showing one of theslide plates in two posit-ions; Fig. 8 is a Aperspective view of a part of the interior of the 'lock showing the lift in a raised position to allow the bolt and slide to be moved; Fig. t is a vertical transverse section through the center of the key; and Fig. 5 is a separate perspective view of the lift.

The same part is indicated by the same letter of reference in all the figures.

The nat-ure of my invention consists in providing a lock with two sliding plates one of which, when the bolt is thrown out, will close the key hole on the side opposite to that on which the key is inserted, and further in providing a straddling lift or catch which holds the bolt and slides in the position given to them by the key, all as hereinafter more particularly described. The improvements are applicable to locks of any of the usual forms, either mortise or box locks.

Referring to the drawings, A marks the frame or box of the lock; B the wards or guides on which the bolt is supported and slides, and which have keyholes for the passage of the key; C the key; D the bolt; E the straddling lift composed of two plates united by a saddle or cross piece; the two plates receive the shank of the bolt between them; F the pin which serves as a hinge to the lift, and also passes through the bolt and slide plates which move on it by means of slots as shown; G the slide plates placed immediately inside of the outside plate of the lock, and supported by and sliding on pin F; H the latch bolt of any ordinary construction; J the spring attached to a pin and controlling the latch H as well as the lift E; K the saddle or catch which unites the plates that form the lift E; this saddle has a notch in it for the reception of the end of spring J, and its ends project beyond the sides of the plates as shown in Fig. 5; L the 'key hole; L the position 'of the keyhole in theslide'plate'when 'thrown forward by the key 'to close `the `ilok; IM Ashoulder in slide forward; N, N, notches in bolt and slide vplates to receive the catch K.

The slides G should be made of steel or some hard metal and have each a key hole for the passage of the key. The upper part of these slides is thicker than the lower part as seen in the sect-ion Fig. 4 and the notches for the key are cut in the upper and thicker portion. There are slots in these slides which enable them to move back and forth on the pin F, in obedience to the impulse of the key. The key is so constructed that it will not in revolving move the slide next to the keyhole into which it is inserted, but the slide on the opposite side of the lock. The arrangement of the bits for this purpose is clearly shown in the section Fig. 4.

The operation of my improved lock is as follows: When unlocked, the keyholes are all in line with each other, and the key may be inserted from either side. The catch K is also forced down by the spring J into the notches N, N, in the bolt and slides, and holds them in the retracted position as shown in Fig. l. The key is now inserted, and, as it is turned, it raises the lift E, and liberates the bolt and slides. The bolt is thrown out by the bit which is applied to it, and, at the same time, the slide G, which closes the key hole at the end of the key, is thrown forward by the end bit. The lift E then falls by the action of the spring J, and the catch K fits into a new set of notches, and. holds the bolt and slides in their new position;

The advantages of this improved lock are great security united to simplicity of construction and consequent economy.

Having thus described my invention what I claim is l. The slides G G constructed, arranged and operating substantially as described.

2. The double lift E constructed and operating as described.

JAMES J. HAMILTON.

Attest:

W. D. SHEPHERD, THOMAS C. DoNN. 

